https://www.theregister.co.uk/2018/04/11/mark_zuckerberg_house_congress_facebook/

Facebook CEO Mark Zuckerberg used today’s grilling in Congress to point the finger at dodgy app developers and Cambridge academics – but appeared to expose huge holes in his knowledge of the way his own business works.

Making his second appearance in front of US lawmakers this week – appearing before the House of Reps' Energy and Commerce Committee – Zuckerberg quickly settled into the swing of looking sombre, stressing just how much more he wished he’d done in retrospect, and promising he'd have his people reply to that tough question in more detail after the session.